'Absolutely insane:' Severe storms expected in central US; tornadoes touch down in Oklahoma

Severe weather season is in full swing across the central and southern U.S. this week: Back-to-back storm systems are forecast to lash portions of the regions with thunderstorms and tornadoes, the National Weather Service said.

The first system will trigger severe storms with damaging winds, very large hail and strong tornadoes Monday in parts of Kansas and Oklahoma. The Storm Prediction Center has issued a Level 4 "moderate" risk for severe weather on Monday in northeastern Oklahoma. This includes the Tulsa, Oklahoma, metro area.

"Intense severe thunderstorms are expected across portions of northern Oklahoma and far southern Kansas, mainly between about 3 to 11 p.m. CDT," the Prediction Center warned.

A tornado watch has been issued for parts of Kansas and Oklahoma until 10 p.m. CDT. By 5:30 p.m. CT, a tornado struck down southeast of Tulsa, Oklahoma, the National Weather Service said.

"Radar is detecting debris," the weather service wrote. "This tornado is doing damage."

Another tornado struck near Seminole, Oklahoma, around 8:00 p.m. CT, according to the National Weather Service. Severe storm damage was also reported in nearby Holdenville, Oklahoma, with flames burning on the roof of a correctional facility and multiple power lines downed by strong winds.

By 9:30 p.m., more than 16,000 customers were without power, according to Oklahoma Gas & Electric.

Meteorologists warned that a line of severe storms was pushing across the state into the evening, with large hail and damaging winds expected. Flood advisories have also been issued for several counties in central Oklahoma.

This system will track into the Ohio Valley region on Tuesday, where cities such as Louisville and Cincinnati are both at risk of severe weather.

The next system is likely on Wednesday and Thursday with severe storms from the southern Plains through the southern U.S., the Weather Service said.

More storms are forecast later in the week and into the weekend. Storm Prediction Center forecaster Evan Bentley described the weather pattern over the upcoming week as “absolutely insane” on Twitter, saying that “Monday, Wednesday, Thursday, Sunday, Monday, Tuesday all have potential to be high-end severe weather days.”

Monday's storm could hit areas that were blasted by severe weather and tornadoes over the past several days. "Some cities impacted by the violent storms on Friday and Saturday will once again be within the hot zone for potential severe storm development as storms transition eastward on Monday," said Alyssa Smithmyer, an AccuWeather meteorologist.

On Friday and Saturday, a potent storm produced strong-to-severe thunderstorms across the country's center, which prompted tornado warnings in at least seven states, AccuWeather said.

One tornado that damaged more than 1,000 buildings in south-central Kansas generated winds up to 165 mph and carved a path of destruction nearly 13 miles long.

The National Weather Service said the tornado that caused extensive damage Friday mostly in the Wichita suburb of Andover and injured several people rated an EF3 on the Enhanced Fujita scale it uses to assess tornadoes.

TRAGIC DEATHS: Community remembers three Oklahoma meteorology students killed in car crash after storm chasing

The Oklahoma State Patrol also said three University of Oklahoma meteorology students were killed in a car crash about 85 miles north of Oklahoma City in Oklahoma on Friday evening as they returned from storm chasing in Kansas.

On top of Monday's severe weather threat, the Storm Prediction Center issued a "critical risk" of fire weather over the southern Rockies on Monday. The fire weather threat is from gusty winds, dry fuels and low relative humidity.

And in Puerto Rico, a rare tornado touched down Sunday, with winds ranging from 86 and 110 mph, Accuweather said. Only 21 confirmed tornadoes have occurred on the island since 1950, according to the National Oceanic and Atmospheric Administration's storm events database.

On Tuesday, the threat of fire weather expands over parts of the Southwest while continuing over the southern Rockies.

Contributing: The Associated Press, The Oklahoma

This article originally appeared on USA TODAY: Severe storms, tornadoes to lash southern, central US this week